– Stat News
SINCE early 1900s, serious viral outbreaks have occurred periodically, caused by pandemic pathogens which span five virus families. Two of these outbreaks have caused more deaths than those reported from Covid-19: the Spanish flu, which appeared in two deadly waves in 1918 and 1919, and the HIV pandemic, which has been around for more than 40 years. In addition, many other viruses, including severe acute respiratory syndrome, avian influenza in humans, Ebola, Marburg haemorrhagic fever, Nipah virus and the current Covid-19, have emerged in recent decades. They have triggered major international concern, raised new scientific challenges, caused major human suffering and death, and caused enormous economic damage.
The full impact of the Covid pandemic has been much greater than what is indicated by the reported death. While the cumulative number of confirmed deaths since the beginning of the pandemic stands at 6.2 million, a recent paper estimates that 18.2 million people died worldwide because of the pandemic, as measured by excess mortality over that period. Excess mortality refers to the number of deaths from all causes during a crisis above and beyond ‘normal’ conditions.
Core of problem
THE rising number of diseases that are communicable between animals and humans reflects a rise in the extent and depth of our encroachment on nature. Increasing interactions between humans and animals, the erosion of biodiversity, the alteration of ecosystems, rapid urbanization and the conglomeration of people living in large cities with limited access to basic services and climate change are increasingly driving the emergence of infectious diseases, most of them from animals, and sometimes with the potential to become pandemics. More than 70 per cent of emerging infectious diseases have their sources in animals – domestic or wild.
The transmission paths take the advantage of human activities such as agriculture, logging, and mining and extraction industries that put animals and humans in closer contact than ever before. Furthermore, the indiscriminate and aggressive use of antimicrobials to prevent and combat infectious diseases, protect plants, preserve food and promote animal growth is giving rise to anti-microbial resistance, causing ‘superbugs’ that withstand the drugs designed to kill or inactivate them or slow their growth. Agriculture and food play a major role in the emergence and spread of diseases and anti-microbial resistance, because of the way food is produced, traded and consumed.
Prevention of emergence of human disease
AS THESE public health crises are not something new, the question that we need to ask is what we have learnt to anticipate and be ready to deal with these threats. Earlier pandemics provided the global community with clear warnings about the danger of fast-moving diseases transferred from animals to humans, which have increased in frequency and severity, causing significant health, social, and economic damage. Each time such a disease struck, resources were hastily poured into fighting the outbreak and calls were made to build back better so that communities and countries would be better equipped to detect and deter subsequent crises.
Unfortunately, in many instances, it seems that once the sense of fear has diminished and the outbreak has been controlled, it is back to the common practice of undervaluing the importance of having in place resilient health systems anchored in robust, integrated, public health and primary care systems. Dealing effectively with these crises requires the capacity to conduct constant disease surveillance, prompt diagnosis and case confirmation, and robust research to understand the basic biology of new organisms and human susceptibilities to them as well as to develop effective and safe countermeasures to control them.
Detecting risk factors
DISEASE surveillance is a critical public health function, but as Covid-19 has made clear, the world woefully underinvests in this function. It is the continuous, systematic collection, analysis, and interpretation of health-related data that serves as an early warning system for impending outbreaks that could become public health emergencies. Such systems support a prompt diagnosis and robust research to understand the basic biology of new organisms and human susceptibilities to them as well as to develop effective countermeasures to control them. The systems also enable monitoring and evaluation of the impact of an intervention, help track progress towards specified goals, and monitor and clarify the epidemiology of health problems, guiding priority-setting and planning and evaluation of public health policy and strategies. An ‘always-on’ early warning system is essential to detect disease outbreaks quickly before they spread, cost lives and become difficult to control.
As humans have extensive contact with the environment and wildlife known to harbor vast numbers of viruses, many of which have not yet spilled into humans, a better surveillance of pathogen spillover and development of global databases of viral genomics and serology, along with better management of wildlife trade, animal health management and substantial reduction of deforestation are vital in preventing and minimizing the impact of future epidemics and pandemics.
Veterinary services have a key role to play in addressing pandemic risks at source. By improving animal health and welfare, they fulfill the fundamental mission of protecting human populations from animal diseases and the other way round. This responsibility is increasingly shared by the broader community because emerging diseases are, to a large extent, driven by numerous factors, such as climate change, land use, agricultural expansion, food systems, urbanization, conflicts and war, and population mobility in an ever more interconnected world.
In all cases, reporting systems with standard procedures and definitions are required to ensure that no cases are missed. Moreover, every case during an epidemic need to be regarded as a public health emergency and investigated immediately as its chain of transmission can be used to determine the extent of virus circulation in the community. Increased laboratory capacity helps in case confirmation. Gaps in the logistics required for collecting specimens and transporting them from the field to the laboratory need addressing. Once established, laboratory support networks can help quickly analyze stool samples, and reference laboratories can provide more sophisticated tests, including the genetic characterization of virus isolates.
In any type of disease outbreak, information and communication strategies are needed to help governments and regional and global institutions deliver timely notification of any outbreaks so that travelers’ advisories can be issued and response plans implemented.
All of these activities require a strong, well trained and motivated cadre of health workers to be able to detect, identify, confirm and inform of new pathogens and people susceptibilities to them as well as to develop effective and safe countermeasures to control them.
Role of pharmacovigilance
BUILDING capacity to conduct through pharmacovigilance – the surveillance of the use of all medicines and vaccines with particular attention to newly authorized drugs – is another critical ‘public good’ investment to ensure that drugs work correctly and that their health benefits outweigh their known risks. The reporting of adverse effects and reactions after the use of a drug is a critical tool to (i) inform decision-making in a health system, (ii) educate and provide guidance for health providers, (iii) help address public safety concern about new medicines and vaccines, and (iv) stimulate prompt policy and regulatory actions.
The overall goal in undertaking this work is to improve patient care and safety with the use of any kind of medication, improve public health and safety in relation to medication use, contribute to the assessment of benefits, harm, effectiveness, and risks of medicines, and encourage safe, rational, more effective and cost-effective use of drugs in countries. The integration of pharmacovigilance with clinical practice and its further development and strengthening are vital tasks going forward to contribute to building resilience in health systems.
AS WE emerge from the Covid pandemic, it is imperative that new policy initiatives and investments in building public health preparedness and response capacity and capability should rest on the recognition that preventing future pandemics means redefining the relationship between humans, wildlife and the viruses that pass amongst us. As public health and animal health are interdependent and bound to the health of the ecosystems in which they exist, it is time to accept that ‘one health’ (or ‘planetary health’) is not only an elegant theoretical construct, but a powerful approach to manage risks. Health sector-centric approaches will, clearly, no longer suffice.
SM Ziauddin Hyder is a senior nutrition specialist at the World Bank Health, Washington DC.